(Terminal Box)
Conventionally, with the terminal box of this type, a plurality of terminal plates formed respectively of a rectangular metal terminal plate body are fixed in spaced relationship inside a box body formed of a synthetic resin and a diode arranged between adjacent terminal plates has its lead terminal portion rigidly attached by means of soldering to a portion of to surface of the terminal plate body (see e.g. Patent Document 1).
That is, the terminal plates and the diode are rigidly unified.
Further, after the diode is conductively connected to the terminal plates, sometimes, sealing of the space of the box body is sometimes effected with charging of a sealing material such as silicone.
With the above-described conventional terminal box, in case this box is used for an attachment target subjected to severe temperature environment such as a solar cell module, the terminal box per se is also subjected to violent change of the ambient temperature.
As described above, the terminal box comprises an assembly of materials having differing characteristics (especially, thermal expansion coefficients) for forming the terminal plate body, the diode, the sealing material, etc. Therefore, there is the risk of these materials being subjected repeatedly to thermal deformations at different ratios (thermal expansion and thermal contraction) in association with changes in the ambient temperature.
As a result, small differences among the thermal deformation amounts of the respective materials are applied repeatedly as a concentrated load to the connecting portions between the diode and the terminal plate body, so that a connection failure may occur. Hence, there was a problem of likelihood of connection failure in the case of significant difference in the ambient temperature.
(Connection Arrangement for Output Cable)
A solar power generation system is configured to generate and supply power with a plurality of solar cell modules disposed in a matrix pattern on e.g. a roof of a building. In order to obtain a desired voltage, each solar cell module is connected in series or in parallel with an adjacently disposed solar cell module. In order to provide a protection for a connecting portion in electrically interconnecting the electrodes of the solar cell modules, a terminal box is attached to the rear face of the solar cell module.
Inside this terminal box, there are provided a plurality of terminal plates to be electrically connected to output terminals of the solar cell modules. Each terminal plate is electrically connected to one end of an output cable for external connection.
For instance, in the case of a solar cell module disclosed in Patent Document 2, over the output cable, there is fitted a waterproof sleeve for securing this output cable to a cable insertion portion. As this waterproof sleeve is provided between the cable insertion portion and the output cable, intrusion of water can be prevented.
In the solar cell module described in Patent Document 2, the waterproof sleeve used for fixing the output cable to the cable insertion portion is disposed in such a manner as to surround the outer coating portion of this output cable. As this outer coating portion tends to be become brittle due to aging degradation as a result of its direct exposure to an outside environment such as ultraviolet rays, a crack may develop therein or its outer shape may be changed or deformed due to frictional wear. If such problem occurs at the contact portion between the outer coating portion and the waterproof sleeve, this may lead to formation of a gap between the outer coating portion and the waterproof sleeve, thus leading to deterioration in the water proof performance of this waterproof sleeve.
(Fixation Arrangement for Output Cable)
Conventionally, in a fixation arrangement for an output cable of a solar cell module terminal box, separately from the electric connection to the terminal plate, there would be provided a cable fastener for fasting or fixing the output cable to the terminal box. This cable fastener is comprised of a cable pressing member and the cable fastener prevents floating detachment of the output cable through its surface contact with the output cable. This cable pressing member is retained and fixed to the terminal box (see e.g. Patent Document 3).
However, looseness tends to develop in the surface contact of the cable pressing member to the output cable. For this reason, if a continued load is applied to the output cable from the outside, this will cause displacement of the output cable relative to the terminal box, thus impairing the electric connection to the terminal plate.